What is logd?
logd runs macOS's unified logging system. Every app and system service writes short messages about what it's doing, and logd collects, compresses and stores them so the Console app and support tools can read them later.
Normally that's a light, steady trickle. If one process starts writing thousands of messages per second, usually because of a bug or an error loop, logd has to keep up and its CPU and disk usage climb.
Why is logd using so much CPU?
- An app stuck in an error loop, logging the same failure constantly.
- Debug or verbose logging left on by developer tools or a beta app.
- A helper crashing and restarting, which logs a burst of messages each time.
How to fix high logd CPU usage
- Confirm it in Activity Monitor. Press ⌘ Space, type Activity Monitor, open the CPU tab and sort by % CPU. Watch
logdfor a minute: short spikes are normal, only steady high usage needs fixing. - Open Console (Applications › Utilities), select your Mac and click Start streaming. The process that floods the list is the one to deal with.
- Quit or update that app. If it's a beta or developer tool, check its settings for debug logging.
- Restart to clear a stuck service.
logdcalms down as soon as the noisy process stops.
More help: How to check CPU usage on a Mac